The present invention relates to a cone mixer having a conic mix receptacle and a swivel arm driven around the receptacle axis.
Such cone dryers or cone mixers are used primarily in pharmaceutics but also in the food industry and the chemical industry.
The problem with such cone dryers and cone mixers is the fact that two different drive motors and associated drives on the one hand rotate the swivel arm around the receptacle axis, on the other rotate the mixing screw rotating in the swivel arm. Based on older patents of the petitioner the drive motors and associated drives are arranged on the receptacle cover and a hollow shaft is run through the receptacle cover whereby the drive arrangement mentioned earlier takes over the drive of the swivel arm and of the mixing screw.
In other words, there is a total of two gear arrangements to be lubricated and monitored, i.e. the gear of the drive set- up in the receptacle center on the receptacle cover, and the pivot gear of the mixing screw in the swivel arm housing.
These bearing sites are separated from one another in space and each bearing site is associated in a known fashion with a lubrication arrangement for lubricating the slip rings, and with a product barrier chamber if any. With the lubrication arrangement for lubricating the slip rings, the slip rings ought to be lubricated constantly during the operation of the cone screw mixer whereby the lubrication arrangement ought to be such that the lubricating liquid does not penetrate into the receptacle and cannot soil the product. To this effect, product barrier chambers are known that prevent the lubricating liquid for the slip rings to reach into the product space.
However, such arrangements are known only in agitator receptacles, i.e. receptacles which do not operate with a swivel arm and a mixing screw rotating therein.
However, significant difficulties arise as soon as a cone dryer or a cone mixer is to be equipped with such a bearing and sealing arrangement.
Indeed, it is especially difficult to equip with a slip ring lubrication and a product barrier chamber the bearing and sealing unit in the upper area of the swivel arm housing in which the mixing screw rotates. When the mixing screw itself is driven in a rotating manner and the swivel arm rotates around the receptacle axis, this involves revolving gear arrangements which are difficult to access from the outside. Until now it is known that a receiver receptacle is arranged on the revolving swivel arm and in which the slip ring lubricating fluid is present. However, this offers the disadvantage that this receptacle must be contained in the product area and that as a result there is the danger of the slip ring lubricating fluid escaping from the receptacle if damaged and of soiling the product. There is also an undesirable clearing space as a result of arranging this receptacle with the outside ducts. In addition, a lubricant check of the receptacle arranged in the product area is not possible during the operation of the cone dryer or mixer.
In addition, it has not been possible until now to arrange a product barrier chamber in the bearing unit between the mixing screw and the swivel arm housing.
The task of the present invention therefore is to further develop a cone dryer or mixer of the type mentioned earlier so that the bearing and sealing arrangement between the mixing screw and the swivel arm housing is provided by a lubricating receptacle accessible from the outside.
An essential feature of the present invention is that the outside receiver receptacle provides for a concurrent lubrication of the central bearing and sealing arrangement on the housing cover in connection with the sealing arrangement revolving with the swivel arm between the swivel arm and the mixing screw.
In other words, the present invention proposes a duct system which supplies the central bearing and sealing unit in the receptacle center as well as concurrently the bearing and sealing unit in the swivel arm housing in which the mixing screw rotates.
This offers the distinct advantage that an outside receiver receptacle can now be used which supplies simultaneously and synchronously both of the sealing and bearing arrangements referred to above. This makes it possible for the first time to monitor and to guarantee the tightness of the bearing of the swivel arm and of the bearing of the mixing screw together during operation.